Skip to content / Đến nội dung
ThichHocToan.com

MathNet 2004 — Part 01 Question 108

Math Olympiad Vault · MathNet 2004 — Part 01

Question 108

A ray emanating from the vertex $A$ of the triangle $ABC$ intersects the side $BC$ at $X$ and the circumcircle of $ABC$ at $Y$. Prove that
$$
\frac{1}{AX} + \frac{1}{XY} \geq \frac{4}{BC}.
$$